Clinical Research Directory

Inclusion Criteria: Participants are eligible to be included in the study if the following criteria apply: * Completion of XTMAB-16-201 study: completion of Week 12 (Part A) or Week 24 (Part B) assessments. * Participants from XTMAB-16-201 Part A and Part B should be on a stable steroid dose for at least 2 weeks prior to informed consent/Day 1 of XTMAB-16-202 (Day 1 should occur at the next scheduled dosing visit on the assigned dose frequency cohort of XTMAB 16 201 ± 2 weeks). Exclusion Criteria: Participants are excluded from the study if any of the following criteria apply: * Evidence of treatment-related AEs requiring treatment discontinuation per XTMAB-16-201 protocol observed in XTMAB-16-201 study. * Evidence of treatment failure observed in XTMAB-16-201 study per protocol definition. * Pregnant or breastfeeding women or women who are planning to be pregnant during the course of the study.